Cheapism: Best activity trackers under $70

For many people trying to lose weight or get in shape, wearing a fitness tracker is a little like having Jillian Michaels follow them around and motivate them to keep moving — but without all the yelling. These gadgets fasten around a wrist or clip onto clothing to detect steps, distance and calories burned. They sync with a computer or mobile device via Bluetooth to provide analysis of the data they collect and monitor activity over the long term. Although the technology has some limitations, the best fitness trackers paint a fairly accurate picture and encourage users to work toward goals.

Fitbit Zip (starting at $47) is the cheapest option from one of the biggest names in fitness tracking. It’s a clip-on device that runs on a watch battery and comes in five colors. It displays basic stats on a screen and features automatic, wireless syncing with an Apple or Android mobile device or computer within range. The free Fitbit app and online dashboard monitor trends, meals and workouts, among other information. Users draw motivation from badges awarded for reaching goals and the ability to connect and compete with their friends. (Where to buy)

The LifeTrak Move C300 (starting at $46) is worn on the wrist and functions as a watch, displaying the time and date. Reviewers cite the built-in heart monitor as a highly desirable feature that typically shows up only on more expensive fitness trackers. Users must push a button to initiate wireless syncing to a free companion app for Apple iOS and Android or a compatible third-party app. (Where to buy)

The Spark Activity Tracker (starting at $60) ties into SparkPeople.com, a free online community devoted to healthy living. In lieu of a screen, this tiny, black, clip-on device sports lights that indicate progress toward a daily goal. Most users don’t seem to mind waiting until they’re within range of a computer to sync and see precise numbers. An app is said to be on the way later this year. (Where to buy)

Striiv Play (starting at $40) is a sleek, clip-on tracker with an LED display and rechargeable battery. It may be marketed as a humble “smart pedometer,” but like the others, it reports calories burned and distance traveled in addition to steps taken. What’s more, it contains an altimeter for counting stairs climbed. It wirelessly syncs with an app available for most recent iOS devices (but not Android). Reviewers laud the motivational aspects of this tracker, which include competing with friends via Facebook and a game that rewards physical activity. (Where to buy)

While many high-end activity trackers can be worn as a wristband or a clip-on, frugal consumers must choose between the two. Fans of the bracelet design note that many clip-on trackers are so lightweight and discreet that it’s easy to toss them in the laundry along with a pair of pants. The waterproof Spark Activity Tracker can actually go through a wash cycle and come out unharmed. The LifeTrak Move C300 is also waterproof, whereas the others are water resistant. They can stand up to sweat, rain, and splashes but aren’t designed for swimming.